Compounded lubricating oil



Patented Aug. 27, 1946 COMPOUNDED LUBRICATING on.

Dilworth r. Rogers, Plainfield, and John G. Mc-

Nab, Cranford, N. J assignors to Standard Oil Development Company, a corporation of Delaware No Drawing. Application May 10, 1943, Serial No. 486,428

25 Claims.

This invention relates to lubricants and methods of preparing the same, and more particularly to mineral lubricating oil compositions for use as crank case lubricants for internal combustion engines and to addition agents suitable for retarding the normal deterioration of such oils and for improving other properties of the same. It also relates to materials which may be used generally for inhibiting normal oxidation and deterioration of organic materials.

It is known that the addition of certain types of metal organic compounds to lubricating oils improves various properties thereof, such as their oiliness characteristics and their performance in engines, particularly manifested in the maintenance of a clean engine condition during operation. Various metal compounds which have been used for such purposes include the metal derivatives of such organic compounds as fatty acids, naphthenic acids, alcohols, phenols, and ketones. However, these various metal compounds generally have the disadvantage of tending to corrode alloy bearings, such as the cadmium-silverand copper-lead bearings now so Widely used in automotive engines; and this is especially true in engines which operate at relatively high speeds and high temperatures. It is an object of the present invention to provide a new class of addition agents for oils which are to be used as crank case lubricants for internal combustion engines and which exhibit the desirable properties of promoting general engine cleanliness, reducing ring sticking, piston skirt varnish formation and the like, and which not only do not exhibit the corrosion promoting tendencies characteristic of many of the above metal compounds, but also inhibit the corrosiveness of oils to which they are added.

The new class of .products which have been found in accordance with the present invention to be highly satisfactory as addition agents for lubricating oils and to be readily obtainable are the products obtained by the reaction of elemental sulfur with certain metal phenates and thiophenates, more specifically, the calcium, barium, strontium, magnesium, and zinc phenates and the corresponding thiophenates containing as substituents in the aromatic nucleus one or more alkyl groups having a total of at least five carbon atoms. It has been found that such reaction products are unusually satisfactory in maintaining engine cleanliness, in inhibiting bearing corrosion, in being stable in the presence of water and in being adapted to use with a wide variety of lubricating oil base stocks.

Furthermore, these products can be prepared with relatively little expense and without the use of costly solvents or equipment. Sulfur-containing materials whichrequire sulfur halides for their manufacture must usually be prepared in special corrosion resistant vessels whereas those of the present invention, using only elemental sulfur, do not require special equipment and can even be made in ordinary grease kettles.

The new sulfur-containing compositions herein described are also useful as anti-oxidants and for other purposes when incorporated in organic materials other than lubricating oils, as will be more fully explained hereinafter, and in many cases it is not necessary to have alkyl groups present to impart sumcient solubility. The invention includes the reaction products of sulfur with compounds analogous to the phenates and thiophenates, but containing selenium and tellurium in place of oxygen or sulfur, and with compounds in which aromatic nuclei other than benzene nuclei are present.

The invention includes the reaction products of sulfur with not only the normal phenates and thiophenates and the like, but the basic metal phenates and thiophenates as well. In a normal phenate of a divalent metal the ratio of metal to phenol is 1 to 2, as in the following formula:

g In a basic metal phenate the ratio of metal to phenol may be 2 to 2 or even 3 to 2. In the case of a 2 to 2 ratio the formula may be These basic phenates are formed, for example,

by reacting phenols with more than the amount pared by the reaction of alkylated phenols with halides of sulfur to give alkylated phenol thicthe aryl groups.

I ethers or disulfides which are then converted to metal salts by appropriate means. .Such products "have the general structure in which the sulfur is present as a bridge linking In the above formula M is a metal, R is an alkyl substituent and n is a small integer, usually 1 or 2.

The products of the present invention however,

which are prepared by first converting alkyl phenols to their metal salts and then causing .the

directly to the :metal through secondary valence forces, as in the following formula:

which probablyrepresents a product formed when two atomic proportions of sulfur are reacted with one molecular proportion of barium tert.-octyl phenate.

One basis .for believing that the sulfur is atalthough for some purposes corresponding compounds containing tin, lead, cobalt or nickel will also'be found to be desirable. T in the formula represents either a hydroxyl group or the group- (OMMXAr where M, X, and Ar have th meanings given above and n is 0, l or 2. Compounds particularly suited for the purposes of the present invention are formed by reacting sulfur with a compound of the formula- (RAIX)2M where R represents at least one alkyl radical attached to the nucleus, the total number of carbon atoms'in all of such alkyl radicals being at least 5 when the compound is to be dissolved in tached to metal rather than to carbon is that a during the reaction of metal phenate with sulfur there .i .no evolution of hydrogen sulfide. Anotheris that when the product is treated with "hydrochloric acid it breaks down to an alkylated phenol, 1osing both metal and sulfur. On the other hand, similar treatment of a metal alkyl phenol sulfide with hydrochloric acid causes loss of metal only and the final product is the alkylated phenolsulfide.

As .has already been pointed out; it is intended that the present invention include products of reaction of sulfur not only with normal metal phenates but also with the basic metal phenates where :the ratio of metal of phenol is greater than 1 to 2 :and may be .as high as 3'to 2. Such products are very easily obtained and are believed to .have the same type of structure as those from the normalmetal phenates, i. e., the sulfur is attached directlyto the metal.

'I'henew class of addition agents employed in accordance with the present invention may be defined in its broadest scope as the reaction products of elemental sulfur with a compound having .the formula ArXMT Inthisfformula. Ar is an aromatic nucleus and may, forillustration, be a benzene nucleus, or it mayconsist of ap'lurality-of rings, as in'biphenyl,

or it may be aacondensednucleus, exemplified by naphthalene, anthracene and the like. X in the ,formula'is a nonemetal of group VI of the perihydrocarbon oils, other symbols having the meanings given above. It should be understood that the above general formulas include compounds in, which various substituent atoms or groups may be attached to the aromatic nucleus, such as alkyl groups, aryl groups, carboxyl groups, hydroxyl groups, alkoxy groups, sulfhydryl groups, halogen atoms, metal substituted carboxyl groups,.metal substituted hydroxyl groups, metal substituted sulfhydryl groups, etc. Alkyl radicals attached to the nucleus will preferably have a total'of 5 to 12 carbon atoms in all of such groups, but in some cases there may be as many as 16 to 20 carbon atoms in a single group or a plurality of groups. If more than one alkyl group is present in a single molecule, whether or not attached to the same aryl nucleus, such groups may be alike or different. Also included within the class of metal derivatives defined above are the metal salts of phenol sulfides and alkylated phenol sulfides.

Some of the more preferred products to be used in accordance with the present invention are the products to be obtained by reacting sulfur with the following compounds:

Barium tertiary octyl phenate Barium di-(tertiary octyl) phenate Calcium tertiary octyl phenate Barium di-(tertiary amyl) phenate Barium cetyl phenate Zincisohexadecyl phenate Calcium salt of petroleum phenols Barium salt of wax-alkylated phenol.

Magnesium salt of octadecyl cresol Barium salt of phenol alkylated with refinery olefin polymers Barium salt of tertiary octyl phenol sulfide phosphoric acid, activated clay, etc. Conveniently, olefinic material such as petroleum refinery gases, containing mixtures of olefins, may be used,

or preferably individual olefins may be employed,

'such as butene, amylene or an olefin polymer,

such as di-isobutylene or tri-isobutylene. High molecular weight alkylated phenols may also be used, for example, those prepared by condensing phenols with chlorinated paraffin wax, chlorinated petrolatum, or with a chlorinated kerosene or gas oil. Naturally occurring phenols, such as those obtained by alkaline extraction of certain petroleum stocks or those obtained from cashew nut shell liquid or from other vegetable sources may likewise be used. Halogenated or nitrated phenols will also find application in this invention, particularly if the final additive is to be employed in extreme pressure lubricants.

One class of alkyl phenols which are particularly preferred are those which have been prepared by alkylation of phenol with an olefin polymer such as diisobutylene or a refinery butene polymer oil. Alkylation of phenol with about an equimolecular proportion of diisobutylene gives para-tert.-octyl phenol, also known as diisobutyl phenol or tetramethy butyl phenol. This phenolic material is especially desirable because of its ease of synthesis and because products made from it are highlysa'tisfactory for the present invention. In many instances, however, a higher degree of alkylation may be advantageous and for this reason the phenol may be alkylated with as much as two molecular equivalents of diisobutylene to give, under proper conditions, essentially di-tert.-octy1 phenol, or it may be alkylated with other olefin polymerssuch as triisobutylene, other isobutylene polymers, or a normal butene polymer. It should be understood that in many cases the alkyla'tion products may be mixtures of various compounds rather than entirely one specific alkyl phenol and that such mixtures may be used in practicing this invention.

For converting the phenolic materials-to metal phenates any convenient and effective means may be employed. For example, sodium or potassium salts may first be formed by reaction with sodium or potassium hydroxide and those salts then converted to the desired divalent metal salts by double decomposition. Another method which may be used is the reaction of an alcoholate of the desired metal with the alkylated phenol. When it is possible, the most convenient method is to react the alkylated phenol directly with the oxide or hydroxide of the desired metal. Thus, the barium salts can be prepared directly by adding barium hydroxide to a mineral oil solution of the alkyl phenol at an elevated temperature.

By employing more than the theoretically required amount of divalent metal hydroxide or oxide in the neutralization, it is possible to prepare basic metal salts of the alkylated phenols, that is, salts in which one valence of the polyvalent metal is satisfied by a hydroxyl group. Reaction it is more convenient to carry out the reaction with the aid of solvents, particularly high boiling hydrocarbon solvents, such as xylol or a petroleum fraction. A particularly preferred reaction medium is a lubricating oil fraction, since the final reaction product can thus be obtainedas a mineral oil concentrate of the desired additive. Such concentrates may be conveniently stored or shipped as such to save weight and space and may "later be readily'blended with a lubricating oil products of sulfur with basic metal alkyl'phenates are particularly useful in extreme pressure lubricants and are also advantageous in motor oils prepared from naphthenic base stocks.

When reacting sulfur with a metal phenate it is usually preferable to use from 2 to 3 atomic proportions of sulfur for each atomic proportion of metal, since in general this range imparts optimum, corrosion inhibiting properties to the product. If too large a proportion of sulfur is used, oils containing the resultant additives tend to stain copper or alloys containing the same. The best results are usually obtained when about 2.5 atomic proportions of sulfur are added for each atomic proportion of metal.

Although these proportions are generally preferred for the preparation of crankcase oil additives, lower or higher percentages of sulfur may be employed when the additives are to be used as antioxidants for other organic materials, and as addition agents for extreme pressure lubricants.

If desired, the products used in accordance with this invention may be prepared by the simulbase stock in the desired concentration to form a finished lubricating oil blend.

Other preferred classes of products useful in accordance with this invention are those obtained by the reaction of free sulfur with metal salts of alkylated phenol sulfides and with metal phenate salts of alkylated hydroxy carboxylic acids and their carboxylate salts, for example, the barium salt of tertiaryoctyl phenol sulfide and the barium phenate-zinc carboxylate of lauryl salicylic acid.

It is likewise often practical to apply this reaction with free sulfur to other organic com pounds containing the --OM group, such as the metal alcoholates or the metal ketonates; for example, calcium octadecylate, barium salts of wax alcohols, etc., to form compositions useful as lubricating oil additives.

The additives may generally be prepared by first dissolving an alkylated phenol in a mineral oil or other suitable solvent and treating the same with a metal hydroxide, e, g., Ba(OH)2.8H2O, at to 210 C. After a further period of heating, free sulfur is added, whereupon almost instantaneous reaction occurs, the solution assuming a deep red color and becoming more fluid. After additional heating the product is filtered, giving a concentrate of the desired additive. If a calcium salt is to be prepared, a less direct reaction is preferred, since the reaction of alkylated phenols with calcium oxide or hydroxide does not proceed as readily as in the case of barium compounds. Calcium alkyl phenates are preferably prepared, by reacting alkyl phenols with calcium methylate or other calcium alcoholate. As to temperatures, thealkylated phenol may be reacted with a metal hydroxide or alcoholate at 90 to 210 0., preferably at to 190 C. Subsequent sulfurization may also be carried out at 90 to 210 C., preferably at to 190 C. It has been found that products prepared by sulfurizing at 180 to C. are the most desirable from the standpoint of water resistivity and freedom from the tendency to stain copper.

It has been found; when preparing these additives in mineral oil, that good results are obtained.

if a minor proportion of a higher alcohol, such as lauryl, cetyl, stearyl, wool fat alcohol and the like, is added to the reaction mixture in which the compounds of the present invention are prepared. It has been determined b test that substantially none of the higher alcohol enters into the reaction. This alcohol reduces foaming during the process and acts as an auxiliary solvent for the final additive. The best results are obtained by adding a sufiicient quantity of the alcohol to give a concentration of about 3% to 15% in the final additive concentrate.

Generally, the additives of the present invention 7 are most advantageously blended with lubricating oil base stocks in concentrations between the approximate limits of 0.02% and 5.0% and preferably from 0.1% to 2.0%, although larger amounts may be used for some purposes. The exact amount of addition agent required for maximum improvement depends to a certain extent on the particular products used, the nature of the luv bricating oil base stock and the general operating conditions of the engine in which the lubricant is to be employed. This same general range of concentration will also be eifective when the additives are to be used in greases and in extreme pressure lubricants, although in the latter instance greater amounts may also be employed.

.As has been pointed out elsewhere in this speoi- I fication, it is often convenient to prepare concentrates of the additives in oil, containing, say, to 75% of effective addition agent, the concentrate later being added to a suitable lubricating oil base stock to give a finished blend containing the desired percentage of additive. Thus, when using a concentrate, 2.5% of this material will be blended with a suitable base stock to give a finished oil containing 1% of effective addition agent.

It has also been found that products of better oil solubility can sometimes be obtained when sulfurizing in the presence of small proportions of olefinic material, such as tetraisobutylene, cracked as or an unsaturated alcohol.

In the following examples are described various preparations of products in accordance with this invention and the results obtained on testing the same in various lubricating oil blends. It is to be understood that these examples, given for illustrative purposes only, do not limit the scope of the invention in any way.

EXAMPLE 1 618 parts by weight of p-tert.-octyl phenol (prepared b reacting diisobutylene with phenol in the presence of SnCh and HCl as catalysts at 20. to 85 C.) and 225 parts by weight of commercial stearyl alcohol are added to 1125 parts by weight of mineral oil (a solvent extracted Mid-Continent paraillnic oil of 52 seconds viscosity( Saybolt) at The temperature is raised to 180 C. and the solution agitated and maintained at this tem perature while 450 parts by weight of barium hydrate (Ba(OH) 2.8H2O) are added gradually. The temperature is held at 180 C. for a period of one hour after the addition of the barium hydrate is completed and then lowered to 170 C. 70 parts by weight of powdered sulfur are added and the temperature is raised to 190 C., and heating is continued until a sample withdrawn from the reaction mixture stains copper only mildly. The mixture is then passed through a filter press yielding a finished product containing 9% barium and 3.3% sulfur. v

For some purposes it is often desirable in such reactions to add slightly less than one molecular proportion of barium hydrate for each two molecular proportions of alkyl phenol in order to avoid the formation of basic barium phenates.

When crude p-tert.-octy1 phenol containing HCl and SnClr catalyst is used, it should be washed with water toremove the HCl. All of the barium hydrate should be added to the phenol solution before the sulfur is introduced to avoid the f ormation of oil-insoluble products.

I EXAMPLE 2 618 parts by weight of p-tert.-octyl phenol 8 mercial stearyl alcohol were added to 1125 parts by weight of a refined mineral lubricating oil of about 52 seconds viscosity (Saybolt) at 210 F., and the mixture heated to C. Over a period of one hour 465 parts of Ba(OH)z.8H2O were added and the mixture was then heated to 170 C. for an additional hour. The temperature was lowered to C., 115 parts of sulfur were added and the temperature raised to 210 C. for a 45- minute period, after which the reaction mixture was filtered, yielding an additive concentrate containing 9.10% barium and 5.06% sulfur.

EXAMPLE 3 A mixture of 618 parts of p-tert.-octyl phenol (prepared as in Example 1), 225 parts of commercial stearyl alcohol and 1125 parts of refined mineral lubricating oil of S. A. E. 20 grade were added at to C. and to this were'added 465 parts of Ba(OH 281-120 over a period of one hour. Heating was continued at 150 to 180 C. for an additional hour, the temperature lowered to 150 C. and 70 parts of sulfur were added. Heating was continued for 45 minutes at 150 to C. and the product wa then filtered. The resulting additive concentrate was a clear red solution which was found to contain 8.88% barium and 3.35% sulfur.

EXAMPLE 4 This preparation is similar to that described in Example 3, except that larger quantities of materials were used and the preparation was carried out in an ordinary laboratory grease kettle. A mixture of 1854 parts by weight of p-tert.- octyl phenol (prepared as in Example 1), 675 parts of commercial stearyl alcohol and 3370 parts of refined mineral lubricating oil of 52 seconds viscosity'(Saybo1t) at 210 F. wa heated to 50 0. Over a 1% hour period 1350 parts oi Ba(OH)z.8H2O were added, after which the temperature was raised to C. and held at this point for one hour. The mixture was cooled to 150 C., 210 parts of sulfur added, and the temperature raised to 195 C. and maintained at this point for one hour- The product was filtered EXAMPLE 5 Over a two-hour period 945 parts by weight of Ba(OH)2.8HzO were added to a mixture of 412 parts of p-tert.-octyl phenol (prepared as in Example 1), 203 parts of commercial stearyl alcohol and 1015 parts of a refined parafllnic mineral lubricating oil of S. A. E. 20 grade, the temperature being maintained at 150 C. The temperature was then raised to 180 to C. for one hour, lowered to 150 C. long enough to permit the addition of 128 parts of sulfur and then raised again to 180 to 190 C. for an additional hour. The product was filtered and yielded a dark colored concentrate containing 43% of additive in mineral oil. Analysis showed that the concentrate contained 17.83% barium and 5.79% sulfur.

EXAMPLE 6 To 1514 parts by weight of a refined paraffin type mineral lubricating oil of 52 seconds viscosity (Saybolt) at 210 F. were added 702 parts of 2,4-di-tert.-amyl phenol and 304 parts of commercial stearyl alcohol. Th mixture was heated to 115 to 120 C. and held at this point while 615 parts of Ba(OH)2.8H2O were added over a 90-minute period. 105 parts of sulfur were then 9 added, heating was continued at 120 C. for an additional hour and then the temperature was raised to150 C. for another hour. The reaction mixture was filtered giving a 40% concentrate of metal-containing additive in mineral oil.

Analysis of the concentrate showed5.82% barium, and 3.38% sulfur.

EXAMPLE 7 This preparation is similar to that of Example 6 except that no stearyl alcohol was used and the barium compound added was Ba(OH)2.H2O rather than Ba.(OH)z.8H2O. 702 parts of 2,4- di-tert.-amyl phenol were added to 1149 parts of a refined paraflinic mineral oil of 52 seconds viscosity (Saybolt) at 210 F. and the mixture heated to 105 C. Then 213 parts of Ba(OH) 2.1120

were added over a period of one hour. Durin the latter portion of this step about 400 parts by weight of 91% isopropyl alcohol were added in alternate portions with the remainder of the barium hydroxide. The temperature was raised to 120 to 130 C. and held at that temperature for one hour. Then an additional amount of 234 parts of the mineral oil were added together with 17 parts of sulfur and the mixture heated for 1% hours at 125 C. The reaction product was filtered to obtain the final additive concentrate,

I which was found to contain 5.59% barium and I 2.52% sulfur.

Exemru: 8

EXAMPLE 9 A solution of 824 parts of p-tert.-octylphenol in 900 parts of benzene was placed in a reaction vessel equipped with a stirrer and reflux condenser, the latter being fitted with a trap to remove water from the reflux tream. The mixture was heated to its boiling point and over a 1 hour period 632 parts of Ba(OH) 2.81-120 were gradually added. Heating and stirring were continued. for 8 hours at refiux temperature to remove substantially all of the water of reaction through the water trap. The product in the reaction vessel consisted of a yellowish viscous liquid. Thi was separted from a small amount A solution of 60 parts by weight of metallic calcium in about 2,000 parts of methyl alcohol was mixed with 618 parts of p-tert.-octyl phenol (prepared as in Example 1) The mixture was heated on a steam bath for two hours with vigorous stirring and then evaporated to dryness with the aid of a stream of nitrogen. The solution was taken up with about 2,700 parts of xylene and heated on a steam bath while a. stream of nitrogen was passed through until about two-thirds of the liquid had evaporated. About 800 parts of additional xylene were then added, followed by 52 parts of sulfur, and the mixture was heated under reflux for three hours. A stream of nitrogen was again passed through the solution until about 900 parts of xylene had been removed. The temperature was gradually raised to 130 C. over a three hour period. Following this the solution was filtered and one-half of the solution was mixed with Y bath, giving a yellow resinous solid, which was Final traces of water were removed by found to contain 6.81% calcium and 5.48% sulfur.

EXAMPLE 11 In the production of secondary butyl alcohol from refinery butenes the latter are contacted with 75% to sulfuric acid at 20 to 30 C. to form butyl sulfuric esters which are subsequently hydrolyzed to form the alcohol. During contact withthe sulfuric acid some of the butenes polymerize and form what is known as a polymer oil. Since the refinery butene feed stock may contain 40-50% of olefinic material in which, in addition to n-butene, 1 to 2% of butadiene, 1 to 3% of isobutene and 1 to 2% of the dimer and/or trimer of isobutene may be present,.tl1e exact nature of the polymer oil obtained is not certain. However, it

can reasonably be assumed that it comprises a -mixture of polymers and copolymers of these various olefins. For the alkylation of phenol to form products useful for preparing materials of the present invention the butene polymer is steam distilled up to 400 F. and the bottoms, boiling essentially from 400 to 650 F., used as the alkylating material. A mixture of parts of phenol and about 240 parts of the polymer oil fraction is saturated with hydrogen chloride at 80 to F. and 10 parts of aluminum chloride are added over a half hour period with stirring. Stirring is continued for an additional 2 /2 hours at 120 F. and the product is then stripped of unreacted material by distilling to 270 F. with nitrogen and then up to 400 F. with steam. The desired alkylated phenol remains as the bottoms from this distillation. The product contains alkyl groups having an average of 16 to 20 carbon atoms per molecule.

EXAMPLE 12 A solution of 280 parts by weight of 016-20 alkylated phenol (prepared as in Example 11) in 90 parts of commercial stearyl alcohol and 450 parts of a refined mineral lubricating oil of 52 seconds viscosity (Saybolt) at 210 F. was placed in a reaction vessel. The mixture was heated to C. and 120 parts of B8.(OH)2.8H2O were added over a period of one hour. Reaction took place readily giving a clear light red solution. The reaction mixture was heated for an additional hour at C. whereupon the color darkened somewhat. It was then cooled to 140 C. and 18.7 parts of sulfur were added. The temperature was held at 140 C. for an additional hour and the mixture then filtered, leaving practically no filter residue. The resulting solution of additive in oil was found to contain 5.59% barium and 2.26% sulfur.

EXAMPLE 13,

alkyl phenate in oil; It contained 6.05% barium. 7

EXAMPLE 14 Blends of lubricating oils containing additives prepared'in accordance with the present invenr tion were submitted to the standard Indianaoxito opposite sides of a stainless steel rod which was-then immersed in the oil and rotated at 600 R. P. M., thus providing suflicient agitation of the sample during the test. Air was then blown through the oil at the'rate of 2 cu. ft. p r hour- To increase the severity of the test, the bearings werewashed and weighed at the end of each four hour perlodand then polished and reweighed before continuing for another four hour period. The results show-the cumulative weight loss at the end of each four hour period. The corrosion life indicates the number of hours required for the bearings to lose 100 mg. in weight, determined by interpolation or'extrapolation of the dation test, described in S. A. E. Journal, vol. 34, 15 data obtained. The results are shown in Table II.

Table II Cumulative Cu-Pb bearing weight loss (mg/ sq. cm.'of surface) on Corrosion life, hours 4 i 8 12 16 20 24 hours hours hours hours hours hours Base oiL .1 5 .181 6 12 26 42 66 283 l8 0 1 12 31' 52 52 28 2 12 21 32 39 190 22 Base o11+0.625% product of Example 6.-. 2 4 8 9 9 10 28 Base oil+0.625% product of Example 12. 3 13 18 32 80 378 21 Base oil+0.625% product of Example 13- 37 88 155 9 page 167 (1934). The results are shown in Table I. The values given represent the number of milligrams of sludge formed from 10 grams of oil at the end of various periods during which the test was run, and the Indiana life represents the number of hours required for 10 grams of oil to form 10 milligrams of sludge. The base oil used 7 in each case was a well refined, solvent extracted araflinic type mineral lubricating oil of S. A. E.

1 Representing 0.25% of metal salt.

EXAMPLE 15 20 grade. It will be seen that the oxidation life of the oil was materially increased by incorporation of the additives. I

Table I Sludge (magi!) gms. of I on Indiana 011 life, 24- 4s 72 96 F"- hours hours hours hours Base oil 0 0 16 65 63 Base 0il+0.625% product of Example 10 0 0 O 30 80 Base oi1+0.625% 1 product of Example 6 0 0 0 35 79 oil to be tested were placed in a glass oxidation It will be readily observed from the. results of these tests that the addition agents of the present invention are very effective inhibitors of alloy bearing corrosion. The data obtained with oil blends containing the products of Examples 12 and 13 show that a metal alkyl phenate has little or no effect as a corrosion inhibitor, whereas when that metal phenate is treated with sulfur by the method of the present invention the product obtained isquite effective in reducing the corrosiveness of the lubricating oil with which it is blended.

EXAMPLE 16 Carbon black dispersion tests were carried out to measure the comparative effectiveness of various oil-soluble additives as agents for dispersing sludge. In these tests 6% by weight of activated carbon was added to each oil blend and thoroughly dispersed in the oil by stirring with an egg beater type mixer for 15 minutes while the temperature of the oil was maintained at 250 F. 250 cc. of each blend was then placed in a 250 cc. graduated cylinder and allowed to settle for 24 hours while the temperature was maintained at 200 F. If an additive is not a disperser the carbon black settles rapidly at this point, leaving clear oil at the top in an hour or two. A very effective disperser will maintain the carbon black in suspension so that no change in the opaque slurry is apparent even after a 24 hour period. With all but the most potent dispersers stratification generally occurs, with a black layer at the bottom (high concentration of carbon black) and a blue opaque layer on top (reduced carbon black concentration). Cases of this type, known as blue line separations, are only detectable in reflected light. The base oil used for each test was a solvent-extracted Mid-Continent oil of 52 Saybolt seconds viscosity at 210 F. Results of the tests are given in Table III and show that the additives of the present invention are very efiective dispersing agents, being even better in 1 Concentrations used were by volume and were those recom mended by the manufacturers.

1 Blue line separation.

EXAMPLE 17 In the following tests, lubricating oil blends containing additives of the present invention were a tested in a single cylinder Caterpillar Diesel engine run under'high temperature, high load conditions, namely, 18.7 B. H. P. output, 850 R.P. M., 195 F. oil temperature and 140 F. temperature for 60 hour periods. After each test was completed the engine parts were examined and given .blend contained 0.5%

prepared with a phenol having a high molecular weight sidechain.

EXAMPLE 18 An additive prepared by the method of Example 1- was blended in 2.5% concentration in an S.- A. E.-30 grade base oil of Mid-Continent origin and submitted to a high speed full load test of 328 hours duration in.a Model 71 4-cylinder General Motors Diesel engine. The conditions of the test were 103 B. H. P. output at 2000 .R. P. M. with 180 1?. water jacket temperature and 230 F. crankcase temperature.

The test results were very satisfactory and were even better than those obtained in a similar 300-hour test on a 2.5% blend of metal alkyl phenol sulfide This of barium tert.-octyl phenol sulfide, 0.5% of barium tertaoctyl phenol disulflde and 0.25% of stearyl alcohol. The oil additive concentrat in the same base.

blend in each of the above tests contained 1% of 1 metal detergent compound.

The demerit ratings obtained in these two tests are given in the following table.

, Table V Engine demerlt ratings Cu-tlfb corg use in to Oil blend 0 beari ng ver- Ring Piston wei ht loss, all zone skirts Sludge mg. eating SAE-30 oil+2.5% of additive concentrate of Example 1 1. 24 2. 64 1.88 0.61 6 SAE-30 oil+2.5% of metal phenol sulfide additive concentrate 1 1. 67 2. 96 '2. 25 1. 1G 6 demerit ratings based on their condition. The individual ratings were weighted according to their relative importance and an overall rating calculated from them. It should be pointed out that the lower the demerit rating the better the engine condition and hence the better the oil performed in the engine. In these tests base oil A was a wellrefinedsolvent extracted paraffinic mineral lubricating oil of S. A. E. viscosity grade, and base oil '3 .wasa solvent extracted Mid-Continent parafiinic oil -of 52 seconds viscosity (Saybolt) at 210 F. Results of these tests are shown in the following table:'

Table IV Engine demerits on R Sk O l Rin ing irt i gs Overall zone varnish filter stuck Base Oil A 1. 41 1.76 l. 2. 25 1 Base oil A+2.5% product of Examp 0. 86 0. 94 0 1.00 0 Base oil A+2.5% product of Example 2 0.78 0. 74 0 1. 25 0 Base oil A+2.5% product of Example 4 0.82 0.75 0 l. 25 0 Base oil A+2.5% product of Eitam e 6 0. 74 0. 65 0. 06 1.00 0 Base 011 A+2.5% product 0! Examp 1.02 1. 31 0 1.00 0 Base oil A+2.5% product of Example 12 0:67 0.63 O 1. 25 0 Base oil B 1.46 1.55 1.00 2.00 1 Base oil B+2 product oi Example 3 0. 74 0.69 0 1.25 0

It will be observed that in each instance the engine condition was much better with the compounded oil than with the base oil, although the degree of improvement was not the same in each case. The greatest increase in engine cleanliness resulted when using the product of Example 12,

Almen testing machine.

dl itguals 1% of effective addition agent, since in each case the additive concentrates contained 40% of metal l me.

These results show that the additive of the present invention was more effective in maintaining engine-cleanliness than was an equivalent concentration of a metal alkyl phenol sulfide additive which has achieved commercial acceptance.

Oil blends of additives of the present invention have also been submitted to 36-hour high temperature Chevrolet engine tests and have given verysatisfactory results as regards maintenance of clean engine condition and as regards inhibition of bearing corrosion, copper-lead connecting rod bearings having been used in the engine for the purpose of measuring the latter quality.

EXAMPLE 19 A refined lubricating oil of S. A. E. 20 grade was tested for load carrying capacity on the Likewise an oil blend comprising the above base oil plus 2.5% of the additive prepared as in Example 8 was submitted to the same test. The Almen test is described in" the Proceedings of the American Petroleum Institute, 13th Annual Meeting, section III, page 119, published December 1932. The results of these tests were as follows:

V The improvement in load carrying ability impar-ted by the additive will readily be noted.

Although in most instances the additives of the' presentinvention will Calcium cetyl phosphate 'ilcient improvement to lubricating oils to give very satisfactory results, still greater improvement may often be obtainedby employing these addition agents in conjunction with other additivesof the detergent type such as metal soaps,

' metal phenates, metal alcoholates, metal phenol sulfides, metal organophosphates, thiophosphates,

phosphites and thiophosphites, metal sulfonates,

- metal thiocarbamates, metal xanthates and thicminim tert octyl phenol sulfide Cobalt tert.-amyl phenol sulfide Calcium mahogany sulfonate Tin salt of wax alkylated phenol sulfide Strontium mahogany sulfonate Magnesium cetyl phenate Nickel oleate Aiuminumwalcium mixed soap of fatty acid from oxidation oi petroleum fractions.

- Calcium isohexadecyl phenol sulfonate Barium octadecylate Calcium dichlcrostearate Nickel amyl xanthate Calcium phenyl stearate mem dibutyl dithiocarbamaie Barium dioctyl dithiophosphate Zinc methyl cyclohexyl dithiophosphate Calcium dihexadecyl monothiophosphite Barium mahogany sulfonates Zinc diisopropyl salicyiate Aluminum naphthenate Magnesium mahogany sulfonates Calcium double'salt acid phenate-xinc 'sul fonate of isohexadecyl phenol sulfonic acid Barium eaten-mm phenol sulfide phenate-barium carboxylate o1 octa-'- decylsalicylicacid Tinnaphthenate M -Particularly advantageous salts of petroleum mahogany sulfonic acids.

Examples of such compositions include the following: I

1 Per cent (1) Additive concentrate of the present in- I vention 1.5

Calcium mahogany sulfonate 0.5" Mineral lubricating oil 98 Q12) Additive concentrate of'the present in- I 'ventiorn 2.5 I r Barium mahogany sulfonate 1.2

lubricating oil 96.3 I it) zinc mahogany sulfonate. 3.5 Additive concentrate of the present inv'ention 2. Mineral lubricating 'oil 94 The lubricating oil base stocks used in the com crudes, or, if, desired, various blended oils may be employed as well as residuals, particularly .those from which asphaltic constituents have been carefully removed. The oils may be refined by conventional methods using acid, alkali and/or of octadecyl phenol sulfonic' are lubricant com- I positionsin which the additives of the present invention are employed in conjunction with metal of themselvesimpart suf clay or other agents such as aluminum chloride,. or they may be extracted oils produced, for example, by solvent extraction with solvents of the type of phenol, sulfur dioxide, furfural, dichloroethyl ether, propane, nitrobenzene, crotonaldehyde, etc. Hydrogenated oils or white oils may be employed as well as synthetic oils prepared,

for example, by the polymerization of olefins or by the reaction of oxides of carbon with hydrogen or by the hydrogenation of coal or its products.

In certain instances cracking coaltar fractions and coal tar or shale oil. distillates may also be used.

voltoiized products may be employed, either alone or in admixture with mineral oils. For the best results the base stock chosen should normally be that oil which without the new additives present gives the. optimum performance in the service contemplated. However,- since one advantage of the additives is that their i usealso makesfeasible the employment of less satisfactory mineral oils or other oils, no strict rule can be laid'down for the choice of the base stock. Certain essentials must of course be observed. The oil must possess the viscosity and volatility characteristics known to be required The lubricating oils, however they may have been produced, may vary considerably in viscosity and other'prcperties depending upon the particular use for whichrtheyfiare desired, but they usually range from about 40 to 150 seconds Baybolt viscosity at 210 F. For the lubrication of certain 'crudes and having a Saybolt viscosity at- 210 F.

of to 90 seconds and a viscosity index of 0 to 50.

I However, in certain types of Diesel service, particularly with high speed Diesel engines, and in gasoline engine, including aviation engine service, oils of higher viscosity index are often preferred, for example, up to 75 to 100, or even higher, viscosity index.

In addition to the materials. to be added according, to the present invention, other agents may also be used, such as dyes, pour depressors, heat-thickened fatty oils, sulfurized fatty oils,

organo-metallic compounds, metallic or other soaps, sludge dispersers, anti-oxidants, thickeners, viscosity index' improvers, oiliness agents, resins, rubber, olefin polymers, voltolized fats,

voltolized mineral oils, and/or voltoiized waxes and colloidal solids such asgraphite or zinc oxide,

. etc. Solvents and assisting agents, such as esters,

ketones, alcohols, aldehydes, halogenated or nitrated compounds, and the like, may also be employed.

Assisting agents which are particularly desirable are the higher alcohols having eight or more carbon atoms and preferably 12 to 20 carbon atoms. The alcohols may be saturated straight and branched chain aliphatic alcohols such as I cetyl alcohol, CsHwOI-I, lauryl alcohol, CnHzsOH, cetyl alcohol, CiOHJIiOH, heptadecyl alcohol,

CnHasOH, stearyl alcohol, sometimes referred to as octadecyl alcohol, Clam-10H, and the like; the

corresponding oleilnic alcohols such as oleyl alcohol; cyclic alcohols, such as naphthenlc alcoholsp and aryl substituted alkyl alcohols, for instance, phenyl octyl alcohol, or octadecyl benzyl alcohol or mixtures of these various alcohols, which may Also, for special applications, animaL :vgetable or fish oils or their hydrogenated or petroleum hydrocarbons, e. g.,

aeoauoe be pure or substantially pure synthetic alcohols.

One may also use mixed naturally occurring alcohols such as those found in wool fat (which is known to contain a substantial percentage of alcohols having about 16 to 18 carbon atoms) and in sperm oil (which contains a high percentage of cetyl alcohol); and although it is preferable to isolate the alcohols from those materials, for some purposes, the wool fat, sperm oil or other natural products rich in alcohols may be used per se. Products prepared synthetically by chemical processes may also be used such as alcohols prepared by the oxidation of paraffin wax, petrolatum, etc. These assisting agents serve to enhance the detergent and sludge dispersive qualities and aid the solubility of the metalcontaining additives and at the same time impart some oiliness properties to the lubricating oil compositions.

In addition to being employed in crankcase lubricants the additives of the present invention may also be used in extreme pressure lubricants, engine flushing oils, industrial oils, process oils, general machinery oils, greases and rust preventive compositions. Also their use in motor fuels, Dieselfuels and kerosene is contemplated. A particular application in this regard is their use in motor fuels containing tetraethyl lead or other anti-knock agents, the additives of the present invention serving not only as anti-oxidants for the fuel, but also as stabilizers for the anti-knock agent itself.

Since these additives exhibit antioxidant properties and are believed also to possess the ability to modify surface activity, they may be employed in asphalts, road oils, waxes, fatty oils of animal or vegetable origin, soaps, and plastics. Similarly, they may be used in natural and synthetic rubber compounding both as vulcanization assistants and as antioxidants, and generally they may be used in any organic materials subject to deterioration by atmospheric oxygen.

The present invention is not to be considered as limited by any of the examples described herein which are given by way of illustration only, but it is to be limited solely by the terms of the appended claims.

We claim:

1. An or anic material containing a stabilizing quantity of a reaction product of at least 2 gram atoms sulfur with 1 mol of a compound having y the structurewhere Ar is an aromatic nucleus. X is a nonmetal of group *VI of the periodic table, M is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, magnesium and zinc, and 'I is a member of the class consisting of H and (OMnXAr, where M, X and Ar have the meanings given above and n is a number of the class consisting of O, 1, and 2,.

2. A hydrocarbon product containing a stabilizing quantity of a reaction product of at least 2 gram atoms of sulfur with 1 mol of a compound of the formulas- RArXMT where Ar is an aromatic nucleus, R represents at least one alkyl radical joined to said nucleus, all of such radicals having a total of at least 5 carbon atoms, X is a member of the group consisting of oxygen and sulfur, M is a divalent where Ar is an aromatic nucleus, R represents at least one alkyl radical joined to said nucleus,

all of such radicals having a total of at least 5 carbon atoms, X is a member of the group consisting of oxygen and sulfur, and M is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, bar.- ium, strontium, magnesium and zinc.

4. A lubricating oil according to claim 3 in which X of the formula represents oxygen.

5. A lubricating oil according to claim 3 in which Ar of the formula represents a benzene nucleus and X of the formula represents oxygen.

6. A mineral lubricating oil containing a stabilizing quantity of a reaction product of sulfur with a metal alkyl phenate, in which the alkyl radicals have a total of at least 5 carbon atoms and in which the metal is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, magnesium and zinc, such reaction product being obtained by reacting from about 2 to about 3 atomic proportions of sulfur to each atomic proportion of the metal of the metal phenate.

7. A lubricating oil according to claim 6 in which the alkyl radical of the phenate is an octyl radical and in which the metal is an alkaline earth metal.

8. A lubricating oil according to claim 6 in which the alkyl radical of the phenate is a p-tert.-octyl radical.

9. A lubricating oil according to claim 6 in which the metal is barium.

10. A mineral lubricating oil containing a stabilizing quantity of a reaction product of at least 2 gram atoms of sulfur with 1 mol of a product obtained by reacting barium hydroxide with a p-tert.-octyl phenol.

11. A mineral lubricating oil containing a stabilizing quantity of the reaction product of 2 to 3 gram atoms of sulfur with 1 mol of a barium di-(tertiary amyl) phenate.

12. A mineral lubricating oil containing a stabilizing quantity of the reaction product of 2 to 3 gram atoms of sulfur with 1 mol of a barium alkylated phenol in which the alkyl groups contain a total of about 16 to about 20 carbon atoms per molecule.

13. A mineral lubricating oil containing a stabilizing quantity of a product obtained by reacting from about 2 to about 3 atomic proportions of sulfur in a mineral oil with 1 atomic proportion of a metal in the form of a metal salt of an alkylated phenol at to 210 C., the metal of said salt being a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, magnesium and zinc, and the alkyl groups of the phenol having a total of at least 5 carbon atoms.

14. A mineral lubricating oi1 according to claim 13 in which the additive was obtained by rei I 19 acting the sulfur with the metal salt in the presence of a minor proportion of a higher fatty alcohol. I

15. A mineral lubricating oil according to claim 13 in which the metal salt is a barium salt and in which the reaction with sulfur is conducted at a temperature of about 170 to about 190 C.

16. A minerallubricating oil containing a stabilizing quantity of a product obtained by reacting a tert.-octyl phenol with barium hydroxide and further reacting the product thus obtained with from 2 to 3 atomic proportions of sulfur for each atomic proportion of metal present, in a mineral oil solvent at a temperature of about 170 to about 190? C., and in which a sufficient quantity of stearyl alcohol is present during both reaction to provide for a concen tration of about 3% to about 15% in the mineral oil containing the final reaction products before I blending with the lubricating oil base.

17. As a composition of matter a sulfurcontaining product obtained by reacting at least 2 atomic proportions of elemental sulfur with one molecular proportion of metal phenate in which the metal is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, magnesium and zinc.

18. As a new composition of matter an oil soluble sulfur-containing product obtained by reacting from about 2 to about 3 atomic proportions of elemental sulfur with 1 molecular proportion of a metal octyl phenate, in which the metal is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, mag nesium and zinc. I

19. As a new composition of matter an oil soluble sulfur-containing product obtained by reacting about 2 to about 3 atomic proportions of elemental sulfur with one molecular proportion of the reaction product of barium hydroxide and a tert.-octyl phenol.

20. As a new composition of matter an oil soluble sulfur-containing product obtained by reacting about 2 .to 3 atomic proportions of elemental sulfur with one molecular proportion of barium di-(tertiary amyl) phenate.

21. As a new composition of matter an oil soluble sulfur-containing product obtained by reacting about 2 to 3 atomic proportions of elemental sulfur with one molecular proportion of a barium alkylated phenate in which the alkyl groups contain a total of about 16 to about 20 carbon atoms per molecule.

22. The method of preparing an oil-soluble sulfur-containin product having anti-oxidant properties in the presence of a hydrocarbon oil which comprises reacting from about 2 to about 3 atomic proportions of elemental sulfur with 1 molecular proportion of a metal alkyl phenate in which the metal is a divalent metal of group II of the periodic table and selected from the class consisting of calcium, barium, strontium, magnesium and zinc and in which the alkyl groups contain a total of at least 5 carbon atoms.

23. The method of preparing an oil-soluble sulfur-containing product having anti-oxidant properties in the presence of mineral oil which comprises reacting about 2 to about 3 atomic proportions of elemental sulfur with one molecular proportion of the reaction product of barium hydroxide and p-tert.-octy1 phenol at a temperature of C. to 210 C. p

24. The method of preparing an oil-soluble sulfur-containing product having anti-oxidant properties in the presence of organic material which comprises reacting barium hydroxide with a tert.-octyl phenol in a mineral oil solution at a temperature of about 90 to about 210 C. and further reacting the product thus obtained, while in the mineral oil solution, with from about 2 to about 3 atomic proportions of elemental sulfur for each atomic proportion of metal present, at a temperature of about to about C.

25. Method according to claim 22 in which a small proportion of a higher fatty alcoholis added to the mineral oil solvent before reacting the phenol with the barium hydroxide.

DILWORTH '1. ROGERS. JOHN G. MONAB. 

